Eighteen months ago, Baltimore post-punk heroes Double Dagger played its final show at the Ottobar. But the trio of Nolen Strals, Denny Bowen and Bruce Willen aren't finished celebrating the band's career.

On April 20 — internationally known as Record Store Day, which falls on the third Saturday in April each year — Double Dagger will host a free record release party at Hampden's Atomic Books. The trio is releasing its final album, a hard-hitting EP called "333," along with a documentary called "If We Shout Loud Enough" that follows the band on its final tour. The film is also part of the 2013 Maryland Film Festival movie lineup.

The release/listening party is from 7 to 9 p.m., and all three members will be in attendance. Strals, Bowen and Willen are creating a fanzine for the party that will consist mainly of tour stories. They'll read from the fanzine and tell other stories that night, as well. The fanzine will be exclusive to Atomic Books and its record store Celebrated Summer.

You can listen to the final song on "333," "Heretic's Hymn," here. The tour documentary, directed by Gabriel DeLoach, features interviews with Dan Deacon, Wye Oak, Future Islands, Thank You and more. The trailer can be seen here or at the bottom of this post. Pardon the scrolling.